The extracellular matrix proteins of the bones and teeth are key elements in the structure and metabolism of these tissues. The goal of this project is to study matrix proteins specific to each mineralizing skeletal tissue in order to understand their molecular structure and biological function. Cell culture systems have been developed to study the biosynthesis and regulation of the bone and enamel matrix proteins in vitro. Experiments designed to unravel the biological function of these molecules are conducted in test systems designed for this purpose. Specific antisera to the proteins are used to explore their variance in physiologically stressed and pathological conditions, both in vitro and in vivo. The genetic alteration of the proteins in disease processes are explored both in animal models and in humans. Preliminary molecular biology studies of the proteins are under way with the expressed purpose of developing additional probes to follow their biological distribution and genetic regulation.